Recently, digital cameras have been widely used instead of optical cameras. A digital camera is a camera functioning as a camera and a scanner by storing any visible object or landscape in a digital storing medium. An optical camera stores an image as an analog quantity; however, a digital camera divides the image into bit maps and records the respective brightness as a digital quantity. Since a digital camera is highly compatible with image data stored in a personal computer, a photographed image can be edited and retouched easily, stored in an inner memory (for example, a hard disk or a memory card), and transmitted to a networked computer.
An image photographed by a digital camera can be retouched by one of the following modes: a sepia mode, a tungsten mode, and a sharpening mode. The sepia mode is an image processing mode for processing the entire image into a mono-color such as brown, the tungsten mode is an image processing mode for processing the entire image by emphasizing the color red in the color balance, and the sharpening mode is a processing mode for clarifying the image by shielding low frequencies and maintaining high frequencies using a low frequency shielding filter.
However, in a conventional digital camera, noise (here, noise means irregular pixel values in the image) or an undesirable object in the image (for example, blemishes on a person's face) may be retouched using an image tool, such as Photoshop®, after transmitting image data to the computer.